In apparatuses of this type, the shuttle is designed to carry out autonomously during a relative long period, for example a year, round trips between two predetermined levels, for example one round trip per day. During these movements, an on-board item of instrumentation, supplied by batteries of accumulators also contained in the shuttle, carries out measurements of various parameters of the environment, e.g., force of the subsea currents, water temperature, etc. Some shuttles are equipped to transmit corresponding signals to a floating buoy which retains the upper end of the cable, and the buoy in turn, retransmits its information to orbiting satellites.
One essential problem concerning these shuttles resides in its propulsion means. In fact, driving by means of a motor would lead to an excessive volume of batteries of accumulators.